For single- or multi-color printing of a recording medium, for example of a single sheet or of a belt-shaped recording medium made from the most varied materials (for example plastic, paper or thin metal films), it is known to generate image-dependent potential images (charge images) on a potential image carrier (for example a photoconductor), to ink these potential images in a developer station (inking station) and to transfer-print the image so developed onto the recording medium.
Either dry toner or liquid developer can thereby be used to develop the potential images.
A method for electrophoretic liquid development electrophotographic developing) in digital printing systems is, for example, known from EP 0 756 213 B1 or EP 0 727 720 B1. The method described there is also known under the name HVT (high viscosity technology). A carrier fluid comprising silicone oil with ink particles (toner particles) dispersed therein is thereby used as a developer fluid. The toner particles typically have a particle size of less than 1 micron. Something close to this can be learned from EP 0 756 213 B1 or EP 0 727 720 B1, which are components of the disclosure of the present application. Described there are electrophoretic liquid developing methods of the cited type with silicone oil with toner particles dispersed therein as a carrier fluid and additionally a developer station made up of one or more application rollers for wetting the potential image carrier with liquid developer corresponding to the potential images on the potential image carrier. The developed potential image is then transferred onto the recording medium via one or more transfer rollers.
In order to secure the toner images in the recording medium, these are fixed there. Previous liquid developer methods are based on a high-ohmic carrier fluid and solid particles (toner particles) suspended therein with a preferential charge.
Given use of a volatile carrier fluid the fixing occurs via evaporation of the carrier fluid and simultaneous fusing of the toner particles under heat effect. The resins of the toner particles adhere with one another and with the recording medium.
Given use of a non-volatile carrier fluid, for example silicone oil, the fixing occurs via reduction of the carrier fluid on the surface of the recording medium and via the simultaneous fusing of the toner particles under heat effect. The reduction of the carrier fluid thereby occurs via, among other things, suction in the recording medium and/or via conditioner rollers that run on the unfixed print image and thereby absorb carrier fluid.
A liquid developer with a hardenable carrier fluid is known from EP 0 455 343 A1. the bonding of the images to be printed with a recording medium occurs via curing of the carrier fluid, whereby a chemical reaction is implemented for curing. The carrier fluid can comprise dimethyl-siloxane bonds. The carrier fluid can additionally comprise a cross-linking agent whose proportion in the carrier fluid can be up to 100%. The curing of the carrier fluid can be initiated by a starter agent.